A cutter blade of this description, e.g. as shown in my prior U.S. Pat. No. 3,764,081, has a generally flat body whose two major surfaces are substantially transverse to the axis of rotation and meet in a sharp cutting edge which occupies a leading position as seen in the direction of rotation. Such a blade may have a variety of outlines, with either straight or curved leading and trailing edges. The blade usually has a more or less pointed tip which sweeps along the inner surface of an annular bowl.
As the fulcrum of the rotating blade advances along the centerline of the toroidal bowl surface, the goods to be chopped (referred to hereinafter as foodstuffs) exert pressure upon one of its major surfaces and also upon a marginal zone of the other surface adjacent the cutting edge, this zone being either flat or convex as its thickness increases from zero at the edge to a maximum at a certain distance from that edge. This marginal zone exerts both a chopping and a whipping effect upon the foodstuffs in order to emulsify them. Those effects increase with the blade velocity, as does the generated heat and the power consumption. Moreover, conventional blades have a tendency to entrain a considerable amount of air radially outwardly with the comminuted foodstuffs; the presence of this air in the chopped goods, e.g. sausage meat, has a tendency to induce oxidation and objectionable discoloration.
It has already been proposed to form the working surface of the blade with a multiplicity of generally radial grooves, terminating short of the cutting edge; see German Pat. No. 1,632,111 and utility model No. 1,718,070. The ridges between these grooves, lying in a common plane or rotation transverse to the axis, do not act cumulatively upon the encountered foodstuffs but are merely designed to improve air circulation.